Here is an idea:
Instead of blocking all the requests an app makes only block the questionable ones.
Do so by providing pre-defined rules people can activate. Defining rules per app can be time consuming so there could be a repo where people share the rules, similar to how Alfred's workflows are shared.
This way Radio Silence can be used with online & offline apps.

@roadtoaether Great idea. There is an insane amount of calls made per app. Even OSX it self calls home more than I like to think about. If you cancel the wrong call your OS start to miss-behave etc. A public blocklist would be awesome! Although it wouldn't be as simple as blocking an web-ad or a torrent-peer. As it could cause systems to start crashing.